This project is designed to continue to supply updated, authoritative Fascicles of Tumor Pathology in Atlas form of the highest quality and at the lowest cost possible for distribution through the American Registry of Pathology, not only to medical students, housestaff, pathologists and other physicians in the United States, but throughout the world. These Fascicles are designed primarily to cover the morphological and biological characteristics of the whole range of tumors afflicting the human race, but should include some pertinent examples from animal tumors, both spontaneous and induced. They set standards of diagnosis and terminology widely used the world over and thereby permit comparison of disease incidence, behavior and results of therapy.